Protected amino-functional initiators and amino-terminated polymers and their production

Abstract

N,N-bis(trialkylsilyl) amino-terminated polymers are prepared by treating p-lithio-N,N-bis(trialkylsilyl) aryl amine with a diene monomer and the resulting polymers are converted to a mono- or di- primary aryl amine-ended diene polymer directly by acid hydrolysis. The amine-ended polymers may be homopolymers of a conjugated diene which contain 4 to 8 carbon atoms or copolymers of such conjugated dienes or copolymers of such a conjugated diene and a vinyl monomer.

We claim: 
     
       1. The method of producing a terminally functional lithium-termnated polymer which comprises (a) reacting a monomer from the class consisting of (1) conjugated dienes containing 4 to 8 carbon atoms, (2) mixtures of such conjugated dienes and (3) a mixture copolymer of such a conjugated diene and a vinyl monomer and (b) an initiator of the formula (SiR 3 ) 2  --N--Ar--Li in which R is an alkyl group of 1 to 8 carbon atoms and Ar is from the class consisting of phenyl, tolyl, xylyl and naphthyl, (c) in a non-protic solvent at a temperature of -50 to 100° C. 
     
     
       2. The method of claim 1 in which the initiator has the formula [Si(CH 3 ) 3  ] 2  --N--C 6  H 4  --Li. 
     
     
       3. The method of claim 1 in which the lithium-terminated polymer produced is hydrolyzed with an alcohol at substantially 25° C. and the lithium is replaced with hydrogen. 
     
     
       4. The method of claim 1 in which the lithium-terminated produced is hydrolyzed with an alcohol at substantially 25° C. and the lithium is replaced with hydrogen and is then further hydrolyzed with dilute acid at a temperature of substantially -50 to 100° C. and the SiR 3  groups are replaced by hydrogen. 
     
     
       5. The method of claim 1 in which the lithium-terminated polymer is reacted with Cl 2  --Si--R' 2  in which R' is phenyl or an alkyl group of 1 to 8 carbon atoms. 
     
     
       6. The method of claim 1 in which the lithium-terminated polymer is reacted with Cl 2  --Si--R' 2  in which R' is phenyl or an alkyl group of 1 to 8 carbon atoms, and the reaction product is hydrolyzed with a dilute acid at a temperature of substantially -50° to 100° C. and the SiR 3  groups are replaced with hydrogen. 
     
     
       7. The method of claim 1 in which the lithium-terminated polymer produced in hydrolyzed with an acid at a temperature of substantially -50°-100° C. and the SiR 3  and the lithium are replaced by hydrogen.